Method and apparatus for sealing containers



Oct. 31, 1944. w. D. BELL 2,361,365

METHOD AND APPARATUS FOR SEALING CONTAINERS Filed June 1, 1942 11 Sheets-Sheet 1 INVENTOR William D Bell.

'1- ATTO R N EYS Oct. 31, 1944. w 1 BELL 2,361,365

METHOD AND APPARATUS FOR SEALING CONTAINERS Filed June 1, 1942 11 Sheets-Sheet 2 v INVENTOR -WiHiam D; Bel l- BY 1 AIIORNEX mom Oct. 31, 1944. w, BELL 2,361,365

METHOD AND APPARATUS FOR SEALING CONTAINERS I Filed June 1, 1942 11 Sheets-Sheet 3 SOURCE OF GAS INVENTOR William QBQII.

W. D. BELL Oct. 31, 1944.

OR SEALING CONTAINERS Filed June 1 1942 METHOD AND APPARATUS F 11 Sheets-Sheet 4 w w no mumaew R r. mam R W 2m w ,n MC mm M Q v M J Oct. 31, 1944.

W. D. BELL 2,361,365

METHOD AND APPARATUS FOR SEALING CONTAINERS Filed June 1 1942 ll Sheets-Sheet 5 5s 72 9 96 97 98 74 0 1m 102 I03 393% 40 |02Q Q5 73 W727 34 4 ggu 40 INVENTOR WiHiom D. Bel i,

ATTORNEYS w. D, BELL 2,361,365 METHOD AND APPARATUS FOR SEALING CONTAINERS Filed June 1, 1942 ll Sheets-Sheet 6 [fl/x 2 80- 7/%//\ 55 .7 9

. NVENTOR W' 'cam D. Bell.

BY 7X rToRNEYs Oct. 31, 1944. w. D. 551.4. 2,361,365

METHOD AND APPARATUS FOR SEALING CONTAINERS Filed June 1, 1942 ll Sheets-Sheet '7 INVENTOR Wilhelm D. Bell.

0a. 31, 1944. D, B L 2,361,365

METHOD AND APPARATUS FOR SEALING CONTAINERS Filed June 1, 1942 ll Sheets-Sheet 8 g 109 vs m Us In gig j l/ullllki K NVENTOR Wilhom D. Bell ATTOR N EYS Oct. 31, '1944. w. D. BELL 2,361,365

METHOD AND APPARATUS FOR SEALING CONTAINERS Filed June 1, 1942 11 Sheets-Sheet 9 INVENTOR W|I||am D. B21 I.

ct. 31, E944 3 w. p. BELL 2,361,365

METHOD AND APPARATUS FOR SEALING CONTAINERS Filed June 1, 1942 ll Sheets-Sheet 10 .INVENTOR William D. Bell.

ATTORNEYS Get 31, 1944. w. D. BELL METHOD AND APPARATUS FOR SEALING CONTAINERS l1 Sheets-Sheet 11 Filed June 1, 1942 wsdquuknom NVENTOR WIHIQrn D. Bell.

ATTOREYS Patented et; 31, 1944 UNITEE STATES PATENT METHOD AND APPARATUS FOR. SEALING CONTAINERS Application June 1, 1942, Serial No. 445,296

13 Claims.-

My invention relates to method and apparatus for sealing containers. It has to do, more particularly, with a method of producing a partial vacuum within the sealed containers, and apparatus by means of which this can be readily ac complished.

This application is a continuation-in-part of my co-pending application Serial No. 325,393, filed March 22, 1940, which issued as Patent No. 2,284,631 on June 2, 1942, in'which Idisclose a method of producing the desired partial vacuum within the containers by first introducing into the space between a closure cap and the open mouth of the container to which it is to be applied a sufiicient quantity of combustible gas to form a combustible mixture, igniting the combustible mixture, permitting the burning gases to expand, and then sealing the closure onto the container.

With a correctly proportioned mixture of combustible gas and air, combustion will spread quite rapidly through the mixture, with a rapid rise in temperature and a correspondingly rapid increase in volume and decrease in density of the burning gases.

By sealing the closure on to the container as nearly as possible coincidental with the greatest volume of the expanded burning gases, the head space of the sealed container will contain only the gaseous products of combustion of low density which; upon cooling to normal temperature, will result in a considerable reduction in pressure or partial vacuum.

This method of packaging not only results in the production of a partial vacuum in the head space of the containers but leaves within the head space an atmosphere of inert gases from which uncombined oxygen has been eliminated 'by the combustion. The fiash'temperature of the burning gases is quite high, resulting in effective sterilization of the entire head space of the containers, but itis of such short duration that it has no injurious effect upon either ,the cap, the container, or the material being packaged. For this reason this process results in better preservation of the contents of the con' tainer than it is possible to obtain by comparable prior art processes.

In my co-pending application Serial No. 325,393, I disclose apparatus for performing this basic process disclosed therein, in which a mechanically reciprocated sealing head is used to close the gap between the closure cap and the container and to completely seat the closure onto the finish of the container.

In the operation of this machine I found that the seating of the closure upon the mouth of the container brings about a very sudden drop in pressure within the container. This is due to the lack of oxygen to sustain combustion and to the very rapid absorption of heat from the burning gases by all of the interior surfaces of the head space. This extremely rapid drop in pressure is in all eiiects equivalent to the quick application of an external force tending to seat the closure upon the container, and is just as effective for that purpose as pressure applied by mechanical means.

When properly utilized, this significant fact makes possible a much simpler and more useful machine for sealing containers in'which the operations can be performed at a high speed and while the containers are in uninterrupted motion. In addition the sealing operation may, when the type of closure requires, be performed in two or more steps, the vacuum being produced as the closure is applied to the container, to be followed later by a further mechanical operation to force the closure into frictionally sealed position on the container or otherwise anchor the closure to its container. M

This method of initially sealing the canon-the container by use of a combustible mixture will I result in the creation of a partial vacuum within the container which will be sufilcient to hold the closure upon the container and prevent the access of air to the head space of the container. This method may be employed with various types of caps. With the side seal cap, which is now commonly in use especially on glass containers, the closure will be initially lightly seated upon the container but in sealing contact therewith. It may be desirable, subsequently, to subject the side seal cap to mechanical pressure to force it into its final frictional sealing position with re lationship to the container. However, a substantial period of time may elapse between the initial application of the closure and its final sealing upon the container by mechanical means. Simi* larly, with this method, a cap may be employed which will be initially seated on the upper end of the container by atmospheric pressure and, subsequently, the skirt-thereof may be contracted by mechanical means into association with a bead on the container which will serve to anchor the cap in position. Thus, an initial air -tight seal will first be made according'to my invention and subsequently, even after the lapse of a substantial period of time, a permanent seal may be effected by means of mechanical pressure.

In the case of a top seal cap now commonly in use especially on glass containers, which may be used with my method, atmospheric pressure will seat the cap on the container in sealing contact therewith and the vacuum created within the container will be sufficient to hold the cap firmly, with an air-tight seal, upon the container. With this type of cap, no mechanical pressure sealing apparatus is required, if the container is sealed according to my method.

One of the objects of my invention is to provide a method and apparatus for applying caps to containers and to create a partial vacuum in the upper end of the containers wherein the cap is initially sealed on the container by atmospheric pressure.

Another object of my invention is to provide a method and apparatus of the type indicated for bringing about an extremely rapid drop in pressure in the head space of a container beneath a cap guided into position relative thereto which will cause seating of the cap in sealing contact with the upper end of the container.

Another object of my invention is to provide a continuous method and apparatus for sealing caps on containers in the manner indicated in the preceding paragraphs.

Another object of my invention is to provide a continuous straight-line machine wherein the containers and caps may be continuously and progressively fed into association with each other, a combustible mixture is introduced into thehead space of each container and ignited and the cap is drawn down into sealing contact with the container, the sealed container then being moved to a suitable position.

Another object of my invention is to provide a continuous machine of thetype indicated in the preceding paragraph which is of simple and inexpensive construction but which will have a very high sealing capacity, will seal the containers effectively and will seal the containers economically,

Another object of my invention is to provide a. machine of the type indicated having novel means associated therewith for guiding the caps into proper position to be appliedto the containers and for preventing them from being applied in tilted position.

Another object of my invention is to provide a machine of the type indicated having novel means for guiding the containers into sealing position and for supporting them during the sealing operation.

Another object of my invention is to provide a method and apparatus of the type indicated for sealing containers, wherein a combustible mixture is employed to seal the cap on the container and to create an effective vacuum, which is of such a nature that the proper combustible mixture will be provided within and about the mouth of the container even though vapor or steam would ordinarily be present in the head space of the container at the beginning of'the sealing operation.

In general, it is the usual practice to move the containers during the entire process of filling and sealing on constantly moving endless conveyors on which the containers may be placed mor or less at random. It is the purpose of this invention to provide suitable apparatus for applying closures to the filled containers as they move along such a conveyor, the closure-applying or cap-feeding mechanism including in its construction means for producing a combustible mixture of gas and air about the mouth of the containers as the closures are being applied, and for igniting the combustible mixture and seating the closures onto the containers to produce the desired partial vacuum. The invention also includes novel means for supporting the containers during their progress through the cap-feeding mechanism, and means for insuring the presence of a combustible mixture about the mouth of each container.

More specifically, I preferably employ a straight-line machine. This machine preferably embodies a straight-line continuously moving conveyor upon which the .filled containers may be placed at random. Disposed above the conveyer in spaced relationship is a cap-feeding and guiding means which is adapted to guide caps into association with the upper ends of the containers as they move past the sealing station. At the sealing station, one of the caps is supported in such a position that it will be withdrawn from its support by a container moving into sealing position. Before each successive container reaches the sealing station, it is engaged by novel gripping and guiding means. This means serves 7 to guide the container into proper position at the sealing station and to prevent tilting of the container during the sealing operation. At the sealing station, I provide means for guiding the caps into proper position to b applied to the containers and means for preventing them from being applied in tilted poistion to the containers.

I also provide at the sealing position, means for charging the proper combustible fiuid Within and about the open mouth of the container to forms. combustible mixture and means for igniting said mixture at the proper instant. This means functions as each container moves into sealing position and engages the cap which is supported in downwardly inclined position by the cap-feeding and guiding means so that the upper end of the container will engage the skirt of the cap. A charge of combustible gas is supplied automatically when the cap is withdrawn from the supporting means by the container and this charge will be supplied into the head space of the container beneath the cap. Withdrawal of the cap from its support also automatically actuates igniting means which functions to ignite the charge of gas supplied to the head space of the container. The cap will be guided into position relative to the upper end of the container as the charge of combustible gas is ignited. Ignition of the combustible gas mixture causes a rapid expansion of the gaseous content of the head space of the container. As soon as combustion cea'ses, the products of combustion beneath the cap cool very rapidly with a consequent drop in pressure beneath the cap and within the head space of the container. The drop in pressure within the head space of the container is so rapid, as a result of the very rapid cooling of the products of combustion, that atmospheric pressure will snap the cap into sealing position and will be sufficient to initially seal the closure upon the container. This action is possible because the temperature of the gases entrapped below the cap is so high and the specific gravity so low that cooling, with a corresponding drop in pressure, is so rapid that the cap will be drawn down into firm sealing relationship with the upper end of the container.

After the cap is applied to the container and is initially sealed thereon in the manner indicated above, the containers may be moved to a station where mechanical means is used to effect permanent sealing of the containers. Whether or not the mechanical means is used for effecting permanent sealing will depend upon the type of closure being used to seal the container. With some caps, mechanical pressure will be desirable to effect the final sealing but this mechanical sealing may occur a considerable period of time after the initial sealing has been effected. With some caps, such as a top seal cap, the final sealing with mechanical pressure will not be neces sary.

In order to aid in understanding my method of applying the closures and of producing the partial vacuum, an embodiment of the invention is illustrated in the accompanying drawings. However, it is to be understood that there is no intention to limit the invention to this detailed embodiment.

In these drawings similar character of reference designate corresponding parts and Figure 1 is a perspective View, partly broken away, of a machine which I preferably provide for performing my method.

Figure 2 is a side elevational view, partly broken away, of the top portion of the machine shown in Figure 1.

Figure 3 is an end elevational view of the portion of the machine shown in Figure 2.

Figure 4 is a plan view of the sealing unit and associated mechanism of my machine.

Figure 5 is a vertical sectional view taken substantially along line 5-5 of Figure 2.

Figure 6 is a vertical sectional view taken substantially along line 66 of Figure 2.

Figure 7 is a vertical sectional View illustrating the container withdrawing a cap from its support and showing means for displacing vapor or steam from the upper end of the container.

Figure 8 is a view similar to Figure 7 but showing the combustible mixture being charged beneath the cap which is being withdrawn by the container.

Figure 9 is an enlarged view similar to Figure 7 but showing, by dotted lines, how the cap being withdrawn by the container controls the charging of the combustible mixture beneath the cap into the container.

Figure 10 is a view similar to Figure 9 and illustrating how further withdrawal of the cap actuates the charge igniting means.

Figure 11 is a view similar to Figure 10 but showing the cap in its initially sealed position on the container.

Figure 12 is a detail in perspective, partly broken away, of the charge-supplying and igniting mechanism. 1

Figure 13 is a perspective view of the mechanism shown in Figure 12 but taken at a different angle.

Figure 14 is a view, partly in vertical section and partly in side elevation, of mechanical pressure sealing means which may be employed if desired.

Figure 15 is a horizontal sectionalview taken through a fan which may be employed for supplying air into the head space of the container.

Figure 16 is a vertical sectional view taken substantially along line I6l6 of Figure 15.

Figure 17 is a plan view of mechanism which may be employed for gripping the container during the sealing operation. 7

Figure 18 is a view similar to Figure 8 but showing a difierent type of cap being applied to the container.

Figure 19 is a view showing how the cap applied in Figure 18 may be crimped in final position.

Figure 20 is a view similar to Figure 18 but showing another type of cap being applied to the container.

Figure 21 is a view, partly in side elevation and partly in vertical section, of the sealing mechanism andiassociated parts of a modification of my machine.

Figure 22 isa perspective view of a portion of the mechanism shown in Figure 21.

Figure 23 is a top plan view, partly broken away, of the mechanism shown in Figure 21.

With reference to the drawings, and particularly to Figure 1, I have illustrated one form of my apparatus as comprising generally a supporting table and conveyer unit I, a vacuumizing and sealing unit 2, a container gripping and guiding unit 3 and a mechanical pressure sealing unit 4. The unit I will feed the containers continuously into association with the unit 2 where a cap will be guided into association with the upper end of the container, a combustible mixture will be charged beneath the cap and the mixture will be ignited, the rapid drop in pressure in the head space resulting from this serving to draw the cap down onto the container. While the container is associated with unit 2, it will be gripped by the unit, 3. The unit 4 will serve to apply mechanical sealing pressure to the cap and may or may not be used, depending upon the type of cap employed.

The unit I is in the form of a table having four legs 5 which support a top plate 6 and a base plate I. As shown best in Figures 1, 3 and 4, intermediate the side edges of the top plate 6 a pair of longitudinally extending spaced strips 8 are secured thereto. These strips extend the full length of the table. Intermediate the strips 8 a third longitudinally extending strip 9 is provided which is secured to the top plate 6. These three strips serve to provide longitudinally extending channels l0 (Figure 3) on top of the plate 6 which receive a pair of chains ii. The chains H are of the sprocket type. and extend longitudinally through the channels H1. The chains slide on the top surface of plate 6 and project slightly above the bars 8 and 9 so that they will support the bottom of a container, in the manner shown in Figure 3, out of contact with the bars.

The chains H are endless chains and pass around double sprocket units 82 and 83 disposed at opposite ends of the table. The sprocket units i2 and I3 are rotatably supported by brackets Hi disposed at oppositeends of the table and being bolted thereto, as shown in Figure 1. The bracket it which supports the sprocket i2 is provided with a vertical bearing [5 which receives a rotatable shaft I6. This shaftiS has a bevel pinion il keyed on its upper end which meshes with a bevel gear I8 keyed on the outer end of the horizontal shaft H) which supports the sprocket unit 52. The unit ii is also keyed on the shaft H9. The lower end. of shaft It has a pulley 2i! keyed thereon. It will be apparent that rotation of this pulley 20 Will drive the conveyer chains ii.

The pulley 20 is driven by means of an endless belt 25. This belt 2i is driven by a pulley 22 which is keyed on the vertical shaft 23 that is rotatably carried by bearing plates 5 and i. The pulley 22 is disposed intermediate the height of the shaft 23. The lower end of the shaft 23 has another pulley 2e keyed thereon. This pulley 2c is driven by means of a belt 25 which is driven by the lower pulley 26 of a multiple pulley unit 2'2? 38 is energized, the chain of screws 4|.

gear unit 23 which, in turn, is driven by an electric motor 30. The units 23 and 38 are supported by the base plate 1. Thus, whenever the motor conveyor will be driven continuously. 1

The unit i isgdisposediat a level spaced vertically above the chain conveyer: depending upon the height of the container being sealed. The

unit 2 is disposed in alignment with the conveyer substantially midway between the side edges of the table. Furthermore, it is disposed intermediate the length of the conveyer and table. Containers placed at random on the chain conveyer behind the unit 2 will be moved progressively, by the continuously moving 'conveyer, into association with the unit 2.

The unit 2 includes a downwardly and forwardly inclined cap chute 3|. This chute 3| (Figure 1)' comprises a pair of spaced guide rails 32 which are in the form of angle members. These rails 32 are properly positioned to support caps 33 which are disposed in edge-to-edse relationship. A bar 34 disposed intermediate guide rails 32 and above the rails serves to prevent the caps from riding up on each other as they slide down the chute. The upper end of the bar 34 is turned upwardly, as at 35, to facilitate insertion of the caps. The lower end of the bar 34 is supported by an inverted U-shaped bracket 36 which is secured to the rails 32. The lower end of the bar 34 is turned downwardly, as at 340. (Figure 2).

The lower ends of the guide members 32 are rigidly secured to the forwardends of a pair of forwardly projecting portions 31 (Figure 1) of a block 38 by means of screws 38s. This block is illustrated in detail in Figures 12 and 13. The block 38 is horizontally disposed and its rear end is rigidly secured by means of screws 330 (Figure 2) to a pair of upstanding supports 33 which have member 48 has a bearing portion 58 formed thereon which is provided with a transverse bearing sleeve in which shaft is mounted for rotatable and slidable movement. A pair of rollers 52 are keyed to the outer ends of this shaft 5|. Spacer sleeves 53 are provided on shaft 5i between rollers 52 and-member 58 to limit longitudinal movement of the shaft. The sleeves 53 are of a proper length to permit limited axial movement of the shaft 5| in bearing 58. Each of the rollers 52 is provided with a circumferential flange 54 at its outer side. The flanges 54 are spaced apart a distance corresponding to the diameter of the cap 33. Thus, flanges 54 of the rollers will engage the side edges of the cap while the circumferences 55 of the main part of the rollers will engage the a top surfaces of the caps adjacent their edges. It

their lower ends rigidly secured to the plate 6 on opposite sides of the chain conveyer. The

guide members 32 rest on inclined ledges 31b formed on the inner surfaces of portions 31 as shown in Figure 12. These portions 31b determine the inclination of the members 32. A second block 46, somewhat similar to block 38, is secured to the upper surface of block 38 by means This block 46 is provided with forwardly projecting portions 42, adapted to be disposed in alignment with the portions 31 of block 38. It is also provided with a forwardly and downwardly inclined front edge 43, between portions 42, which form continuations of the surfaces 31b. The members 32 will also rest on this surface 43 andmay be secured thereto by means -of screws passing into threaded openings 44 formed therein.

As shown best in Figures 1 and 2, the bracket 36 carries a downwardly and forwardly extending rigid arm 45 which is supported midway between and above members 32. This arm 45 extends a substantial distance beyond the lower ends 46 of members 32. and is provided with an upturned lower end 41. It will be noted from Figure 2 that the member 34 terminates at a point above the lower ends 46 of the members 32. Supported above the arm 45 in alignment therewith is a flat spring 48. This spring 48 is attached at its upper end to a block 43 secured to bracket 36 and serving to space the upper end of member 48 from the upper end of member 45. The lower end of the member 48 will normally rest on the upturned end 41 of member 45. The extreme lower end of will be apparent that the rollers 52 are free to rotate and are also free to move laterally to a limited extent. Normally the lower end of flat spring .48, which carries the rollers, will contact the upturned portion 41 of member 45 and the rollers will be supported in the full line position indicated in Figure 2. However, the rollers can be moved vertically against the action of spring 48, as shown by dotted lines in Figure 2.

Associated with the lower end of the cap chute is a lever 56. This lever is illustrated best in Figures 2 and 4. It is disposed between the guide rails 32 adjacent the lower ends thereof. It is disposed in alignment with the lower end of member 34 and its lower end terminates substantially at the lower end of member 34. This lever 56 has its rear end pivotally mounted, as at 51, to a supporting yoke 58. The yoke 58 is carried by a housing 53 which is supported on the upper surface of the block 38 adjacent its rear edge. The housing 53 includes a bracket 68 to which the member 58 is directly-connected. This bracket 60 has a depending portion 6! which has an opening that receives a grommet for a cable 63 that connects to the switch disposed in housing 53. The rear end of lever 56 is formed integral with a sleeve 64, rotatably carried by yoke 58. One end of sleeve 64 carries an integral depending trigger 65. The lower end of this trigger is adapted to engage a push button 66 of the switch 53 when the lever 56 is moved to a certain position. Th lever 56 has a lower inclined portion 61. The extreme lower end 68 of the portion 61 normally projects above the horizontal surfaces of guide members 32 of the cap feed, as shown by the full lines in Figure 2. However, as a cap passes between the downturned portion 340. of member 34 and the end'68 of lever 56, the lower end of the lever is forced downwardly and rearwardly into the dotted line position indicated in Figure 2. The block 48 is provided with a notch with a gas supply control valve 13 which is carried by the block 48. The plunger 12 is normally held in raised position by means of a spring 14 associated With the valve 13. When in raised position, the trigger 65, as shown by full lines in Figure 2, will not engage th push button 66 of switch 53.

The caps which I use for sealing the containers These notches 63 and 1| are may be of various types. In Figures. 1 to- 17, inclusive, .1 have illustrated side seal caps being used. These sid seal caps are commonlyused for sealing glass jars of thetype shown in the drawings and indlcatedby the numeral 15. This glass jar is provided with areduced mouth having a vertical sealing surface 16 and a tapered finish 11. The cap 33is shown as comprising a disk-like body portion 18 having a depending peripheral skirt 19. This skirt carries on its interior a compressible gasket. 80. When the cap 33' is forced down into telescoping relationship with the upper end of the container 15, the gasket 88 will contact withthe vertical surface 16 forming a tight frictional seal. However, it is to be understood that my invention is not limited to the particular type of containeror cap shown in the drawings.

The caps fed into the chute 3| will be in edgeto-edgerelationship, as previously stated. The lowermost cap will slide down to the full line position shown in Figure 2 until it engages the rollers 52. The weight ofthe caps in the chute will be suflicientto force the lowermost cap downwardly past thecooperating portion 34a of member 34 and the portion 81 of lever 56. The lowermost cap will move downwardly until its lower edge moves between the flanges 54 of the rollers 52 and the surfaces 55 of the rollers engage the top surface of the cap. Then downward movement of thelowermost cap will be stopped. At this time, the lower end of member 48 will be contacting the upturned portion 41* of member 45. Thelowermost capis held in the chute by the, rollers and is prevented from tilting by portion 34a. Consequently, the lowermost cap will be held in the fullline position shown in Figure 2, depending from the cap chute and being in such an inclined position that the forward portion of the flange 19 will be engaged by the upper end of the container 15 being moved into sealing position by the .chain conveyer.

As the continuously moving chain conveyer.

moves the container 15 beneath unit 2, the upper end of the container engages the skirt of the cap and withdraws it from the chute. As the cap is withdrawn from the chute, the cap pivots about the rear edges of the rollers depressing the lower endfil of lever. 56. The rollers 52 will be raised during'this action, as shown by dotted linesin Figure 2. The rollers 52 will also move laterally, if necessary, to permit lateral alignment of the cap and container. As the container continues to move, the cap will be guided.. into cooperative position with the upper end thereof and will be positioned thereon. The successive steps of this operation are illustrated best in Figures 9, l and 11.

In order to insure the proper seating of the cap upon the finish of the container, I provide a pair of guide rails 8|. These rails are so positioned that they provide a fulcrum about which the cap rotates to an approximately level position as it is seated upon the container. These guide rails extend longitudinally in spaced relationship and have their rear ends rigidly connected, as at 82, to a yoke 83. This yoke 83 is supported on the rear. portion of block 38 by means of a screw 84 passing through an opening formed in yoke 83 midway between its ends. As shown in Figures 9 and 10, the head of the screw 84 fit into the openin in such a manner that limited universal movement of the yoke relative to the block 38 will be permitted, The guide rails 8| are spaced apart laterally a distance slightly greater than the diameter of the reduced upper portion of the containers. Thus, the upper ends of the containers may move freely therebetween and'they will align with the containers. However, the spacing between rails 8| is such that the skirt of the cap will'be engaged, at diametrically opposed points, when the cap moves downwardly to a predetermined position, as shown by the full lines in Figure 10. As the cap is removed from the chute, its rear edge moves off the block 48 and the guide rails 8| exert a leveling action on the cap, as shown by the dotted lines in Figure 10, and will prevent the cap from bein applied in tilted position on the container. The guide rails 8| are at such a level, as shown in Figure 11, that when'the gasket 80 of the cap is in contactwith the vertical surface 18 of the container, the skirt of the cap will not be in contact with the rails 8|. Thus, the rails will cooperate with the rollers 52 to leve1 the cap relative to the upper end of the container as it is withdrawn from the chute. However, the rails 8| will not interfere with the cap being drawn down into sealing contact with the upper end of the container. The rails 8| may swing laterally or move vertically to a limited extent. Thus, they will cooperate with the rollers 52 in positioning the cap laterally relative to the container. Thus, as the successive containers continuously move beneath the lower end of the cap chute, each container will withdraw a cap which will be guided into position and leveled into horizontal position relative to the upper end of the container.

As each cap is engaged by a container it tilts so that its rear edge depresses the lever 56. It continues to ride on the block 48, holding the lever 56 depressed and the valve 13 open, as indicated by the dotted lines in Figure 9. As the cap is further withdrawn, the rear edge thereof is no longer supported by block 48 but only by the lower end of lever 56, as shown in Figure 10. This will depress lever 58 further and it will be de ressed sufiiciently to move tri ger 65 into a position to actuate the movable control member 66 of the switch on housing 59. The mechanism which is controlledby the switch in housing 58 and by the valve 13 will be described hereinafter. V

In order to supply the proper combustible mixture beneath the cap. as it is bein withdrawn from the chute, I provide the arrangement now to be described. As shown best in F ures 2, 9. 10. .12 and 13, the forward vertical surface In or the block 38 has small i nition chambers 85 formed therein which are open at their forward ends. These chambers communicate at their rear ends with gas and air assa eways 86 extending lon itudinally of block 38. One chamber 85 is provided adjacent each s de of the block.

Intermediate the passages 86 a lon itudinally extending air and gas passa eway 8 is formed which has its forward end even at the surface 1n. All of the passages 86 and 81 are connected" at their rear ends, asshown best in Fi ures 7 and 8. to a transversely extendin air chem-- ber 88 formed in the block 38. Intermediate and directed rearwardly and upwardly. These passages 89 communicate at their upper ends with a transversely extending gas chamber 90 formed in the upper surface of block 38. A

gasket 9| is provided between the blocks 38 and similar shape.

' .ways 89, into passageways 86 and 8l.

duit'I98 leads to a fan or air .with a series of air inlet openings H5.

the impeller II I is rotated. air is drawn through v passage 94 formed in block 49.

j As shown in Figure 5, an inlet passageway 95 Q is formed in the block 49 for supplying a suitable combustible gas to the chamber 93 in which the 89 and. through the passages 89 and. 91, beneath the depending cap. The air impinging against the cap, as shown best in Figure '7, will be defiected into the head space at the upper end of the filled container and will serve to displace any vapor or steam from the upper end of the container. This will insure proper supply of air for combustion, particularly if the contents of the valve I3 is disposed. The passageway 95 is con-- nected byza conduit 95a to a suitable source of combustible gas. The chamber 93 has a large cylindrical lower portion 96 and an upper smaller cylindrical portion 91. "The valve is in the form of a hollow verticallymovable member 98 of The spring I4 normally forces this member 99 upwardly- The enlarged ower portion of member 98 has an upstanding knifeedge annular rib 99, formed thereon, which contacts with asealing ring I99 carried by the top wall of the lower enlarged portion 99 of chamber 93. When the valve is seated in this manner, gas. cannot flow from the lower portion 96 of member 93 into the upper portion 91 thereof. Consequently, gascannot reach the passage 94 which leads into the. chamber 99. However, when I plunger I2 is forced downwardly and moves member 98 downwardly, the rib 99 is unseated from gasket I99. Then gas will flow from the portion 99 of chamber 93 into the portion 91 thereof,

through passage. 94 into the chamber 99. From the chamber it will flow down through passage- A needle valve IN is provided in the passage 94.for regulating the amount of gas which will flow through this passage; This needle valve has a threaded outer portion I92 threaded into block 49. A spring I93 of the compression type is provided on the outer portion of the needle valve between with an air passage I94 formed in a block I95.

secured to the side edge of block 38 as shown in Figures 4 and 12. The block I 95 has a rearwardly extending passageway I99 formed therein at right angles to the passage 94. A valve I91 is threaded into block I95 and into the ,end of passageway I94. 'By means of this valve I91, the amount of air flowing into the chamber 88 may be controlled. The rear end of passage I96 is in communication with an air conduit I98. This conpump I99 s'upported on the base plate I.

The fan I99 is illustratedbest in Figures and '16. It comprises a cylindrical housing II9 having an impeller I I I rotatably mounted therein. An outlet I I 2 communicates with the conduit I98. The impeller I I I is provided with an upwardly extending shaft portion H3 which extends through a hub portion I M projecting upwardly from the housing. "This hubportion is provided openings H5 by the impeller andis forced out .through the outlet I I2. The shaft portion H3 carries a driving'pulley I I6 which is keyed thereon., This pulley IISis driven by means of a belt III which is driven by'the pulley section II 8 of the multiple pulley unit 21.

The fan unit I99 will serve to force air continuously through the line I99 and intothe chamber container have been processed with steam or are hot and are emitting vapor. As the container moves along and withdraws a cap, the valve I3 is unseated and this allows gas to reach the passages 86 and 81, as previously indicated. The air and gas mixture will then be forced out of the forward end of passage 81 beneath the cap and into the upper end of the container as shown in Figure 8. The air and gas mixture from pas sages 86 will first enter chambers 85 and will then pass out into the space beneath the cap.

' When the space beneath the cap and the head space of thecontainer has been supplied with a proper charge of combustible mixture, this mix-' ture will be ignited. This is accomplished by providing spark-producing. means in association carried by and are insulated from the blocks 38.

1 throughout.

When

They may be removably held in position by means of setscrews I22. When the push button 66 of switch 59 is pushed inwardly, this will energize the spark plugs and ignite the gas and air mixture flowing out of the chambers 85. This will ignite the combustible mixture, previously charged beneath the cap and into the head space, The spreading of the ignition throughout the mixture is facilitated by the turbulence created by the flow of air from the chamber 89, through the passages and 81 and out into the space beneath the cap. As previously indicated, the switch 59 will be actuated shortly after the valve I3 has been actuated to supply the combustible gas to the passageways B6 and 81.

Thus, a charge of a combustible mixture is supplied within and about the open mouth of the container and this charge is then ignited. The ignition will occur as the cap is being withdrawn from the lower end of the cap chute, as indicated in Figure 8. The cap will be guided into 1 position relative to the upper end of the container. The ignition of the combustible gas mixture causes a rapid expansion of the gaseous content of the head space of the container. As the combustion subsides, the products of combustion beneath the cap cool very rapidly with a consequent drop in pressure beneath the cap and within the head space of the container. As the combustion ceases, the cap has been leveled into horizontal position relative to the upper end of the container. The drop in pressure within the head space of the container is so rapid, as a resultoi the very rapid cooling of the products of combustion, that atmospheric pressure will press the cap into sealing position as shown in Figures 8 and 11 and will be sufficient to hold the cap down on the container with the gasket IS in sealing contact with the container. The drop in pressure will serve to draw the cap down into sealing contact with the upper end of the container and may draw the skirt downwardly so that the gasket will be in partly telescoping relationship to the surface 76, as shown in Figures 8 and 11. However, the gasket will always be drawn into firm sealing contact with the upper end of the container by the reduction in pressure in the head space of the container beneath the cap. Thus, the cap is initially sealed on the upper end of the container by the ignition of the explosive mixture charged beneath the cap.

In order to guide the containers laterally of the chain conveyer into proper association with the unit 2, I provide diverging guide members 39b which are shown best in Figure 4-. These guide members 39b are carried by the vertical supports 39 intermediate the height thereof, as shown in.Figure 2, and extend rearwardly therefrom. As each container is moved into association with the unit 2, the members 39b will engage it and position it in alignment with the unit 2.

In order to grip the containers and prevent -rearward slipping thereof as each container withdraws a cap from the cap feed, I provide novel container gripping means which functions as the container engages the cap and withdraws it from the chute. It is particularly important to provide this means when small diameter containers are being fed inasmuch as they have a tendency to upset rearwardly when theupper end of the moving container engages the stationarily supported dependent cap. This gripping means is shown best in Figures 1 to 4, inelusive, and 17.

This gripping means-comprises apair of gripping rollers I23. These rollers are disposed at opposite sides of the chain conveyer and adjacent the unit 2. They are disposed horizontally at such a level spaced above the plate 6 that the containers supported by the conveyer and moved successively therebetween will be properly sunported by the rollers. Each of the rollers I23 comprises a wheel I24 (Figure 1) upon which a pneumatic tire I25 is mounted. This tire may be inflated by means of a valve I26. The wheel I24 is provided with a hub I21 which is keyed to the upper end of a shaft I28. The shaft passes down through the plate 6 and is rotatably mounted in a bearing I29 thereon. The center portion of the wheel is normally covered by a removable plate I30. Each of the shafts I28 has a sprocket ISI keyed on' its lower end below the plate 6. An endless chain I32 passes around one of these sprockets and around a smaller sprocket I33 keyed on the upper end of shaft 23. This chain I32 also engages the other sprocket I3I. Thus. the shaft 23 will serve to drive the rollers I23 in opposite directions. These rollers will be driven in such a manner that the peripheral portions thereof will travel in the same direction and at the same linear speed as the conveyer chain.

As indicated in Figure 17, as the container I is brought between the converging surfaces of the rollers I 23, by the continuously moving conveyer. the container is driven firmly but resiliently between the rollers. It will be noted from Figures 2 and 4 that the axes of rollers I23 are substantially in alignment with the lower end of the cap feed. Consequently, the rollers will exert their greatest gripping force on the container as the container is withdrawing the can from the lower end of the cap feed. This is where the gripping action is needed most. Thus,

with this structure, there will be nodang'er of the container being upset as it withdraws the cap from the cap feed. The amount of the gripping action, that is. the resilient force exerted by the rollers on the container, may be varied by variations in pressure of the air within the pneumatic tires I25. As the container moves along, it will pass a line extending through the axes of these rollers and will therefore reach the diverging portions of the roller and will be released.

After the caps have been applied to the containers in the manner indicated, the containers may be subjected to the mechanical pressure sealing unit 0 or its equivalent. Whether or not they are subjected to this unit 4 will depend upon the type of cap being used to seal the containers. If it is a side seal cap of the type previously described, it will be desirable to use such a mechanical sealing unit as the unit 4. However, the unit a need not necessarily be mounted directly adjacent the unit 2, although it is preferred to have it so mounted. The mechanical pressure sealing may occur after a considerable period of time has elapsed subsequent to the initial sealing by the combustible mixture.

The unit 4 is illustrated best in Figures 1, 2, 4 and 14. It comprises a vertically disposed wheel I34 mounted in substantially the same plane as the chain conveyer. This wheel is disposed at a proper'level to force the cap down into the final sealing position on the containers with the gasket 80 in frictional contact with the vertical surface I6 of the container.

The wheel I34 is provided with a band I35 of compressible material. Thus, hub I36 of the wheel is keyed on a horizontal shaft I31. This shaft is rotatably mounted in a bearing I38 provided on the upper end of a vertical support I39. The support I39 comprises an upper portion I40 which carries the bearing I38. This upper portion I40 has a socket in its lower end which receives the upper end of a rod MI and is held in position in the socket by a setscrew I42. The lower end of member I 80 rests on a sleeve I03 which is threaded in the upper end of a'sleeve The sleeve I is clamped to the plate 6 by means of clamping means M5. The rod MI is free to slide vertically in members I43 and IM. A compression spring I46 surrounds the lower end of rod MI and its lower end bears against a nut I41 threaded on the rod. The upper end of the spring bears against the lower end of member I64. Thus, the wheel I34 is resiliently mounted so that it can move upwardly against the force of spring I46 as a container moves beneath the wheel. The vertical position of the wheel may be varied by threading the sleeve I43 up or down on the member M 3.

The shaft I31 has its outer end disposed in a bearing M8 which loosely engages the shaft in or er to permit the necessary vertical movement of the inner end of the shaft. This end of the shaft I31 carries a worm gear I39 which engages with a worm I50 formed on the upper end of the vertical shaft I5I. The lower end of this shaft is carried by a bearing (not shown) secured to the vertical wall of the table. The lower end of this shaft I5I has a pulley I52 keyed thereon. This pulley I52 is driven by a belt I53. The belt I53 is driven by the pulley I54 of the multiple pulley unit 21. The wheel I34 will be driven so that its lower periphery will travel in the same direction and at the same speed as the chain conveyer. Consequently, as the containers are moved betible mixture.

tainer.

into association with this unit, they will be gripped by the unit 3. At the unit 2, one of the caps will be engaged by the container and will be withdrawn from the cap chute. A charge of combustible fluid will be supplied within and about the open mouth of the containerlto form a combus- However, before the combustible gas is supplied beneath the cap, the air current or moisture therefrom and a better combustible mixture will thus be obtained. The combustible mixture will be ignited as the cap is being withdrawn and guided into horizontal position. Ignition of the combustible gas mixture causes a rapid expansion of the gaseous content of the head space of the container. As soon as combustion ceases, the products of combustion beneath the cap cool very rapidly with a consequent drop in pressure beneath the cap and within the head space of the container. The drop in pressure within the head space of the container is so rapid, as a result of the very rapid cooling of the products'of combustion, that atmospheric pressure will press the cap into sealing position and will be sufficient to initially seal the closure upon the container. After this initial sealing action, the container moves into association with the unit 4 which will apply mechanical pressure to effect the final sealing operation. The vacuumizing and sealing operation is performed during the continuous movement of the container through the machine.

In Figure 18, I have illustrated my method and apparatus being used in connection with a different type of cap and container. The cap is provided with a skirt 19a. adapted to be deformed around a bead 16a on the container to mechanically anchor the cap in position. The cap is provided with a side seal gasket 19a and with a top seal gasket 19b. The cap is applied to the container by the unit 2 in exactly the same manner as before. The initial seal will be effected by drawing down the cap with the gasket 19b in contact with the upper end of the container. The vacuum created within the container will be suflicient to hold the cap in position. Then, the container with the cap thereon is moved to another sealing unit 40. which consists of a chuck lb that is adapted to surround the skirt of the cap and to subject the skirt to a bending action, indicated in Figure 19, to cause the gasket 19a to engage the bead 16a and anchor the cap in position. Thus,

the seal is initially eiiected by the unit 2 and the mechanical seal is later effected by the unit 4a.

A long period may elapse between these two sealing operations.

In Figure 20 I illustrate my method and apparatus being employed with a cap of the top seal type. This cap is provided with a top seal gasket 19c adapted to seat upon the top edge of the con- The cap is applied by the unit 2 exactly as before. However, with this type of cap, it will not be necessary to use any mechanical sealing unit. The vacuum created within the container by the unit .2 will serve to retain the cap in position.

In Figures 21, 22 and 23, I have illustrated a unit is the same as in the other machine. The

unit 3a for gripping and supporting the containers as they withdraw the caps from the cap chute. in this instance, embodies a pair of endless belts I23a disposed at opposite sides of the conveyer. Each of the belts is carried by a forward idler pulley I55 and a rear driving pulley I56. The pulley I56 is keyed on a driving shaft I51 which is vertically supported for rotation in a bearing I58. The pulley I55 is carried by a pin mounted on the forward end of a horizontal arm I59 which has its rear end mounted for rotation about the shaft I51. A leaf spring I60 is carried by the hearing I 50 and engages the outer edge of bar I59 adjacent its rear end. Thus, the spring I60 serves to swing the forwardend of the bar I59 inwardly. The shaft I5! is driven in such a manner as to drive the belts I23a in the same direction and at the same linear speed as the chain conveyer. It will be apparent from Figure 23 that the forward end of the belt units will converge towards each other. The normal distance between the forward ends of these belt units will be slightly less than the diameter of the container being sealed. Consequently, as the container moves between these belt units, it will be gradually gripped. Stops ISI are carried by the bearings I58 for engaging the inner edge of bars I59 and for limiting their inward swinging movement. As shown in Figure 23, the rollers I55 are disposed adjacent the lower end of the cap chute 3Ia. Thus, the containers will be firmly gripped adjacent the lower end of the cap chute where the containers will engage the caps, Thus, tilting of the containers rearwardly will be prevented.

- The cap chute 3 la in this instance is practically the same as before. In this machine, the fan for supplying the air current beneath the capat all times is not employed. In sealing some products, this will not be necessary. In this machine, instead of employing a spark-producing means for igniting the gas mixture, I provide a. constantly burning pilot flame.

It will be noted that the lower end of the cap chute has a block member 38a associated therewith. This block member has two forwardly directed orifices 86a at the forward edge thereof.

The rearwardly extending gas passage 81a, formed in this block, connects these orifices to a flow control valve 13a. The valve 13a is normally seated, as shown in Figure 21. It is adapted to be unseated by moving the plunger 12a downwardly. When unseated, the passage 81a is connected to a gas supply passage or chamber 88a. A suitable gas supply conduit 880 is connected to this chamber 88a. A small outlet passage 8812 leads from the chamber 88a and is connected to a gas line 63a. This gas line 63a connects to a pilot valve I20a which is cooled by fins I20b. The forward end of this pilot valve is provided with an orifice I200 which is upwardly directed and extends through the bottom d of a tubular member l20e. This member is located at one side of the lower end of the cap chute. Openings Illlj are provided in the wall of the member I206. This member receives an open top flue member I209 which telescopes therewith. An opening I 20h leads from the member I20e to a point which will be beneath the lowermost cap in the chute. The pilot burner orifice I200 will always provide a constantly burning flame because the line 63a is connected to a constant supply of gas. An igniting nozzle member I20i extends through the modification of my machine. The chain conveyer 76 wall of the chamber I 20e towards the opening mm. The member MM is connected by a passage 81b to the passage 81a which is connected to the valve 12a.

As soon as the control valve 13a is actuated, a charge of gas will be forced outwardly from the orifices 86a and will mingle with the air beneath and about the cap to form a combustible mixture. At the same time, flow of gas will occur through the igniting nozzle I202, which is adjacent the pilot burner orifice I200. The gas issuing from member I202 will be ignited as it passes the pilot flame and will, in turn, ignite the combustible mixture beneath the cap into which it is projected through opening l20h. There naturally occurs a slight interval of time between the issuance of gas from the orifices 86a and the ignition of the mixture beneath the cap by the flaming gas issuing from member I201 through opening liflh because of the longer path traversed by the gas issuing from member i201. This delay is sumcient to permit the intermingling of the gas issuing through orifices 86a with the air in the extended head space beneath the cap.

The plunger 12a is adapted to be moved downwardly by means of a lever 56a. This lever normally projects up into the cap chute substantially the same as lever 56. The lever 56a will be moved downwardly when a cap is withdrawn from the chute and will force the plunger 12a downwardly and unseat valve 13a, allowing a charge of gas to flow through the nozzles 86a. As soon as the cap is withdrawn, the valve will be automatically closed. Thus, the sealing operation with this form of apparatus will be practically the same as before.

It will be apparent from the above description that I have provided a sealing machine and method for applying caps to containers and for creating a partial vacuum in the upper end of the containers wherein the cap is applied to the container in sealing contact therewith by atmospheric pressure. My apparatus and method will continuously apply the caps and seal the containers during their progressive movement.

During sealing of the containers, a combustible charge will be supplied beneath the caps and will be ignited at the proper instant to draw the caps down into sealing position. The drop in pressure beneath the cap within the head space of the container is so rapid, as a result of the very rapid cooling of the products of combustion, that atmospheric pressure alone is sufficient to seal the p pon the container when it is supported in proper relationship to the upper end of the container. The combustion of the charge not only expands and displaces the air in the head space of the container, but also consumes the oxygen therein. Thus, the rarefled gases which remain in the head space of the container after sealing ar inert products of combustion. The desired vacuum is produced without the introduction of moisture and, consequently, the method is particularly useful for sealing dry products.

Various other advantages will be apparent from the preceding description, the drawings and the following claims.

Having thus described my invention, what I claim is:

l. The method of sealing a cap on a container which comprises guiding a cap into position over the container and while guiding the cap into such position first passing a current of air beneath the cap and into the head space of the container to remove vapor therefrom and then charging a combustible fluid beneath the cap and into the -head space of the container to form a combustible mixture, and igniting said combustible mixture to cause the gases beneath the cap and in the head space of the container to expand and to subsequently contract and seating the cap on the container as combustion subsides in sealing position relative thereto.

2. The method of sealing a cap on a container which comprises positioning the cap over the container and while maintaining the cap in such position sweeping the space beneath the cap and about the mouth of the container with air to remove vapor therefrom, then charging such space with a combustible fluid to form a combustible mixture, and igniting said combustible mixture to cause the burning gases to first expand and then contract and means for seating the cap on the container while the burning gases are expanded.

3. A method of sealing and preserving packaged material which comprises sweeping the space within and about the open mouth of a container with air to remove vapor therefrom, then charging such space with a combustible fluid to form a combustible mixture, and igniting said combustible mixture to cause the burning gases to first expand and then contract and sealing the container as the gases contract.

4. A method of closing and sealing a container which comprises supplying a charge of air into the container to remove vapor therefrom, supplying a charge of combustible fluid into the container so that it will mix with the air, igniting the combustible mixture so produced, and then sealing the container.

5. The method of continuously sealing caps on containers which comprises moving the containers continuously, guiding a cap into position over each successive container during its continuous movement, and while guiding the cap into such position charging a combustible fluid beneath the cap and into the head space of the container to form a combustible mixture, and igniting said combustible mixture to cause the gases beneath the cap and in the head space of the container to expand and to subsequently contract, and means for seating the caps on the containers while the burning gases are expandedduring continuous movement or the container.

6. A method according to claim 5 wherein a charge of air is flrst supplied beneath the cap before the combustible fluid is supplied to remove vapor therefrom.

7. The method of continuously sealing caps on containers which comprises continuously moving the containers, supporting caps in position to be engaged by successive containers toapply a cap to each container, and while the cap is being applied to the container charging a combustible fluid beneath the cap and into the head space of the container to form a combustible mixture, and igniting said combustible mixture to cause the gases beneath the cap and in the head space of the container to expand and to subsequently contract and means for seating the cap on the container as the gases contract during continuous movement of the container.

8.. Amethod according to claim 7 wherein a sweepof air is supplied beneath the cap before the combustible fluid is supplied to remove vapor therefrom.

9. A method according to claim 5 wherein the sealed container is subsequently subjected to me- 

